nptl: fix start_thread() for _STACK_GROWS_UP
nptl: fix start_thread() for _STACK_GROWS_UP

This patch adds a working implementation of pthread_create for architectures
where STACK_GROWS_UP.

Signed-off-by: Matt Fleming <144cc4c33a91c3f236fb3354d519b92f95d0c3ce@imgtec.com>
Signed-off-by: Carmelo Amoroso <532378793705a04edd56deb76ad8c0442834d55d@st.com>

joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc